Excess-pressure attachment for clamps



April 14, 1925. I

. L. T. BERGH EXCESS PRESSURE ATTACHMENT FOR CLAMPS Filed May 12. 1924 INVENTOR Low 711381312 Patented Apr. 14, 1925.

PATENT OFFICE.

LOUIS T. BERGH, OF FAIROAKS, CALIFORNIA.

EXCESS-PRESSURE ATTACHMENT FOR CLAMPS.

Application filed May 12,

To (1% whom it may concern:

Be it known that I, LOUIS T. Bnncrr, a citizen of the United States, residing at Fairoaks, county of Sacramento, State of 5 California, have invented certain new and useful Improvements in Excess-Pressure Attachments for Clamps; and I do declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to'improvements in clamping devices, my principal object being to provide an auxiliary clamping device, in the form of an attachment readily applied to an ordinary screw clamp of the C frame type by means of which the power of the clamp is increased considerably. In other words, after the screw of'the clamp has been advanced as far as possible by hand against the parts being held, further and almost I unlimited pressure may instantly and easily be applied-tothe parts to force them still closer together without any twisting strain being placed on the screw; j

The actuating member of. the attachment, once the additional pressure is applied, will not release of itself, but will remain indefinitely in the position to which it has been moved, forming an automatic lock.-

lhe advantages obtainable with this. at- --'tachnient will be evident-to those who have occasion-to use such clamps, and who have at onetime or another expended considerable and sometimes futile efforts inen- -deavoring to draw-two parts together-ff A. further object of the invention isto produce a' sim Jle-and inexpensive device and yetone which will be exceedingly effective for the p urpose for which it is designed.

' These objects I accomplish by -means of such structure and relative ar 'angeme-nt of parts as will-fully appear by a perusal 'of. the following specification and claims.-

.In the drawings similar characters of reference indicate corresponding parts in the several views Figpl is a sid e out-l me of i an ordinary C tachment moved to a sition.

This head projects toward the pad 1924. Serial No. 712,772.-

.' frame clamp, showing my attachment applied thereto 111 a neutral position.

Fig. 2 isasimilar view showing the atpressure applying po- Fig. 3 is afragmentary plan view of a l'no'dified form of clamp-foot o'r pad, for use in certain special work.

. Fig.4 is an enlarged end view of the cam ember on the attachment lever, detached. Fig. 5 is an enlarged sectional view of the head of the attachment, detached.

Referring now more particularly to the characters of reference on the drawings, the" numeral 1 denotes the frame of an ordinary clamp, having a foot-pad 9. and a screw 3 in alinement with the pad, the screw carrying on its end the usual swivelly mounted head 4, positioned to face the pad 2.

These are standard parts, and of themselves form no part of my attachment.

The latter comprises a head 5, of substantially the same diameter as the head 4, and adapted to be loosely hung from the latter by means of lugs 6 provided on the head 5 and adapted tobe bent over the edge of the 7 head 4, as clearly shown in. Figs. 1 and 2, and engages the adjacent surfaceof the parts 7 to be clamped and which are placed between said pad and head 5. Extending tran'sversely through the head 5 is a circular orilice 8 which is centered so that the periphery thereof intercepts andcuts through them ner face ofthe head for-ga certain a-rcuate distance. In other words, a circular rod placed in saidorifice will projectabove the inner face of the head somewhat, the extent of such projection depending 'of course on the location of the center of the orifice/relative to the inner face of'the head.

Itemovably nd turnably fitted in the orificc 8 is aicircular rod 9 having a longitn dinal flat surface 10 cut therein to a depth equal to the projection of the plane of the orifice 8 be'yondthe adjacent face of the head In. other words, if the rod is turned so that the'flat' surface 10 is parallel with the inner face of the head, it will be also in alinement therewith, or at least will not extend outwardly of said face. Connected to or formed integral with the rod 9 at one end thereof is a handle or lever member 11, disposed in a plane at. right angles to the rod.

In operation, the screw 3 is advanced toward the pad 2 to force the parts 7 together as far as possible without using excessive twisting force on the screw.

The adjacent faces of the heads 4 and 5 are then in close contact with each other.

If additional pressure is desired, the rod 9, which is in reality a form of cam, is inserted into .the orifice 8 from one end thereof in the only position then possible,.that is, with the fiat surface 10 the cam alined with the heads, Now on turning the handle in either direction, the flat portion 10 will be moved around in the orifice, and the circular periphery of the cam will engage the head it. Since this periphery will project beyond the plane of the adjacent face of the head 5, the two heads st and 5 will perforce. be separated, and since the screw and pad 2 are then relatively immovable,

the parts '7 will be compressed or drawn closer together. The main cam. being circular, it will remain of itself in any position to which it may be turned. If the parts tend to remain in the latterposition; when once so moved, the cam may be retracted to again place the flat surface 10 thereof in alinement with the face of the head 5,. the screw advanced to take up the spacethen remaining between, the two heads, and the handle 9 then turned to again separate the heads. It will thus be seen that great pres sure can be applied to the parts without twisting the screw or tending to twist the parts.

The additional pressure thus obtainable depends on two, factory-the length. of the handlell, and the distance the periphery of the orifice 8 projects beyond the plane of the head 5, the latter factor of, course gov" crning the form of the cam. In other words, if. the circular portion of the cam, can project but slightly beyond the head, a great leverage will be obtained, but the heads will separate but little whereas with, a greater projection of the cambeyond, the head, a greater movement of the, head 5 WLll be had, but the pressure or leverage. will not be as powerful.

I have in mind, as one use for this attachment, the tightening of wheel. spokes. in the metal fellies of automobile wheels. For such service, the clamp foot is forked as at 2 in Fig. 3, to straddle a spoke, while. the head 5 is socketed on the outer face thereof as shown at 12 in Fig. 5, to receive the-v end of the spoke which projects through the inner face of the felly in the above named form of. wheel construction.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having-thus described my invention what I claim as new and useful and desire to secure by Letters Patent is: v 1.. An excess. pressure attachment for screw clamps including a head adapted to be placed between the head and foot pad of.

the clamps, said heads normally abutting,

and means applicable to said first named head for separating the heads.

2. excess pressure attachment for.

screw clamps including a, head adapted to be placed between the head and foot pad of the, clamps, said heads normally abutting, and means applicable between said heads for separating the same.

,3. An excess pressure attachment for screw clamps including a head adapted. to be pl ced between the head and foot pad of. the. clamps, said heads normally abutting, and cam means mounted in. the first named head and adapted to be moved into engagement with the clamp head to effect a separation of the heads.

4. An excess pressurev attachn'ient for screw clamps including be placed between the head and foot pad of the clamps, said; heads normally abutting, means connecting the heads in a. manner to allow of separation thereof, and cam and at will for so. sepalever means applicable. rating the heads.

5.. An excess. pressure attachment for be placed. between the) head and foot pad of the; cljamps, said heads normally abutting,

said first. named head having a transverse orifice cutting through the. face of said head which lies. adjacent the clamp head, and a cam turnably mounted in, the orifice, said cam having a flat Surface which when parallel to the adjacent facev of the first named head will not project therebeyond.

a head adapted to- 7. An excess pressure attachment for screw clamps including a head adapted to be placed between the head and foot pad of the clamps, said heads normally abutting,

5 said first named head having a transverse orifice cutting through the face of said head i which lies adjacent the clamp head, a circular cam turnably fitted in the orifice, and a flat surface on the cam cut lengthwise therein to a depth not less than the projec- 10 tion of the periphery of the orifice beyond the'plane of the adjacent face of the head. In testimony whereof I afiix mysignature.

LOUIS T. BERGH. 

